Impact fuse



O. WITTEL IMPACT FUSE Filed Feb. 20, 1945 May 10, 1949.

Patented May 10, 1949 IMPACT FUSE Otto Wittel, Rochester, N. Y., assigner to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application February 20, 1945, Serial No. 578,842

6 Claims.

This invention relates to an impact fuse suitable for hand grenades, bombs, and the like. One object Of my invention is to provide an impact fuse which is simple in construction and which is simple to assemble. Another object of my invention is to provide an impact fuse in Which there is a key member which serves both as a safety member and a firing pin. Another object of my invention is to provide an impact fuse which cannot operate the primer in case the fuse has been improperly assembled. Other objects will appear from the following specification, the novel features being particularly pointed out in the claims at the end thereof.

In certain types of impact fuses, the ring pin has been accurately held against operation until an arming pin is removed when the parts are properly assembled, but in certain types of devices it has been possible to assemble the impact fuse improperly and in such a manner that it is not necessary to remove the arming pin to cause the firing pin to operate. My present impact fuse is particularly designed to overcome these diiculties and to provide an extremely simple structure which is so simple to assemble that the difficulties of improper assembly are largely overcome. Moreover, with my improved construction, if the assembly is incomplete, it is impossible to operate the fuse by impact.

lComing now to the drawings wherein like reference characters denote like parts throughout:

Fig. 1 is a section through an impact fuse constructed in accordance with and embodying a preferred form of my invention;

Fig. 2 is a fragmentary sectional View similar to Fig. 1 but with the parts as they would appear after impact and just before the primer is struck;

Fig. 3 is a fragmentary section taken on line 3--3 of Fig. 2.

Since my improved impact fuse is particularly designed for hand grenades it is shown in connection with this type of device although the impact fuse can, of course, be used in any case where it is desired to have impact lire a charge, such as in certain types of bombs and the like.

In the present embodiment of my invention the impact fuse is made up of a simple assembly which can be inexpensively made and readily assembled. As indicated in Fig. 1 the grenade may include a body portion designated broadly as I ywhich is a shell having an inturned annular 'wardly turned flange 5 and an outwardly turned flange l, the latter resting on the flange 2. A cup 8 is supported by the flange 6 and encloses the impact fuse as well as the primer 9 which is struck to set off the explosive charge.

A gasket IIJ supports the head I I, this head being threaded to the adapter 4 and including a pair of upstanding lugs I2, each of which includes an opening I3 through which a safety pin I4 passes, this pin having a loop I5 supporting an operating handle or ring I6.

The safety pin I4 holds a cap I'I in place, the safety pin lying in a groove I8 in the cap. This cap rests on a gasket I9 and a spring 20 normally tends to thrust the cap away from the gasket. This movement of course can only occur after the safety pin I4 has been withdrawn.

There is a spool 2I inside of the cap about which a line 22 is coiled, this line being attached to the cap I'I at one end and to the head 23 of an arming pin 24 at the other end.

The arming pin forms a portion of the impact fuse assembly and extends into a central aperture 25 in a plunger 26 which (as best shown in Fig. 3) is slotted at 21, this slot extending radially to the aperture 25. In this slot 2l there is a key 28 which includes a sharp point 29 forming a tiring This key not only forms a firing pin but is vso arranged that it also provides a safety device preventing the operation of the impact fuse in case of improper assembly.

The key 28 includes a shoulder 30 which may be beveled as shown to engage a Wall 3l on the holder 32. This holder includes a tubular upper end 33 and a thick bottom Wall 34 having a central perforation 35 through which the firing Pin 29 may pass and having a seat 36 for the primer 9. A light spring 3l engages a shoulder 38 on the key 23 and tends to turn this key about the rounded protuberance 40 in a clockwise direction with respect to Fig. 1.

However, as long as the arming pin 24 lies in the aperture 25, the key 28 is held rigidly in the position shown in Fig. 1. It cannot turn because of the arming pin 24 and it cannot move downwardly because of the cooperating shoulders 30 and 3|.

When the hand grenade is to be used the operator pulls out the handle I6 releasing the safety pin I4 While at the same time holding the cover Il with his fingers. When the grenade is thrown the spring 20 will project the cover I1 from its closed position as shown and the line 22 will unwin-d from the spooltZI. Only a short length of line is required but'the air pressure against the `the primer. vice is known and my improvement consists in making the key 23 and the ring pin as shown and described `in one piece so that it cannot be `improperly assembled.

cap l 'l is sufficient to draw the arming pin 24 out of its aperture 25 through the aligned aperture lli in the head l l so that the spring 31 may now rotate the key 28 into the Fig. 2 position and about the curved surface 40. The key is now in a ring position with the pointed end 29 lying above the perforation 35 and above the primer 9. When the grenade makes impact, this sudden shock will cause the plunger 26, which is of appreciable weight, to move downwardly carrying the key 23 with it and causing the pointed end 29 to strike the primer to set ofi the explosive charge.

My improved safety Iiring key 28 is shown `in a known type of impact firing device in that the plunger and holder have been used in connection with a diierent type of iiing pin so that these parts alone are known. However, the construction of these parts will be further described to 'clarifythe operation.

The upper edge of the plunger 26 is rounded at'45 to engage the curved wall 46 of head l l, and the lower part of the holder is rounded at l1 to engage the inside walls of the body member 48,

the reason for this `being that the grenade may strike at a `considerable angle from the axis of 'the Vkey 28 and consequently the rocking motion `of the plunger and holder will cause the firing pin 28 to be moved downwardly into contact with As above explained, this type of de- With earlier types the ring pin was a sepafrate element and this element could be held against movement by safety devices which, if

Aproperly assembled, were entirely satisfactory. Unfortunately, if in the assembly certain parts were omitted, the firing pin could actuate through shock without the cap being removed.

`With my improved device there is no way to improperly assemble the safety device for the ring pin because they are formed in a, single metal .part. `My key 28, if assembled at all, must be placed in the slot 2'! resting against the pin A2l!- 'and whenso positioned it forms the safety device fsnce it cannot slid'e or turn in its position be- "ftwen the plunger and holder.

On the other hand if the key 28 is-inadvertently omitted entirely from the assembly, the ring pin is necessa'rily omitted and, consequently, while the hand grenade would not work, it nevertheless could not "be inadvertently operated without the cap I'l being removed.

I have called my key'an impact fuse. This is intended to cover a fuse whether operated by impact or other means, such as a motor spring in which impact of the key on a primer res a `charge of explosive.

What-li` claim is: 1. `Animpact fuse forbombs comprising a body portion containing explosive material, a primer,

`an apertured plunger telescopically mounted in `key adapted to engage and be restrained from --movement by the holder, an arming pin extending into the aperture in the plunger and engagingthe key, Aa spring engaging the key and holder, said spring being adapted to move the key 1nside' of the holder when said arming pin is removed whereby the shock ofthe bomb coming to 4 rest may cause the plunger to telescope into the holder moving the key to strike the primer.

2. An impact fuse for bombs comprising a body portion containing explosive material, a primer, an apertured plunger telescopically mounted in a holder for the primer, a key carried between the plunger and holder, said key including a pointed end forming a firing pin, a cam on the key adapted to engage and be restrained from movement by the holder, an arming pin extending into the aperture in the plunger and engaging the key, a spring engaging the key and holder, cooperating surfaces on the key and plunger on which the former may rock with respect to the latter under the impulse of the spring when the arming pin is removed, thereby positioning the key for striking the primer upon impact of the bomb.

3. An impact fuse for bombs comprising a body portion containing explosive material, a primer, an apertured plunger telescopically mounted in a holder for the primer, a key carried between the plunger and holder, said key including a pointed end forming a firing pin, a cam on the key adapted to engage and be restrained from movement by the holder, an arming pin extending into the aperture in the plunger and engaging the key, a spring engaging the key and holder, c0- operating surfaces on the key and plunger on which the former may rock with respect to the latter, a slot in the plunger for movably receiving the key, said arming pin aperture intersecting said slot whereby the key may engage the arming pin while lying in the slot, and when the arming pin is removed may turn on the cooperating surfaces into an operative position under the iniiuence of said spring when said arming pin is removed.

4. An impact fuse for grenades or the like comprising a key in the form of a flat plate including a sharp ring pin on one end and a shoulder on the other end, a plunger and a holder slidably supporting the plunger, a recess in the plunger having a wall against which the key shoulder may rest, an aperture intersecting the recess, and an arming pin normally lying in the aperture, said key normally lying in an inoperative position in the recess of the plunger and engaging the holder and arming pin, walls on the key and holder for retaining the former against movement while said arming pin is in the aperture, and means -for turning the key to release the key shoulder from the wall of the recess in the plunger and into an operative position upon removal of the arming pin.

5. An impact fuse for grenades or the like comprising a body portion containing explosive material, a primer, and an impact operated firing device including a plunger having an aperture in the center and a slot extending to the aperture, an arming pin normally lying in the aperture, a holder in which the plunger is slidably mounted, a key lying in the slot and engaging the holder and being restrained from movement by the arming pin and holder, the key including a surface engaging the plunger about which the key may turn, a light spring tending to turn the key against the arming pin, a point on the key forining a i'lring pin, said spring turning the key upon removal of the arming pin into a ring position to be movedtherefrom when the plunger is moved by a shock caused by impact.

6. An impact fuse for grenades or the like comprising a body portion for containing explosive material, a primer, and an impact firing device including a slotted plunger, the slot of which terminates in an aperture, a holder in which the plunger is mounted for limited movement, an arming pin lying in the aperture of the plunger, a key lying in the slot and engaging the arming pin and the holder, said key having an area of such width that it cannot move between the arming pin and holder and lying in an inoperative position relative to the primer, a lug on the key lying against the plunger and means for rocking the key on said lug and turning the key thereon swinging said key into an operative position in which it may slide in the holder when said arming pin is removed, whereby an impact 1 6 REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,304,544 Conrad May 27, 1919 1,339,735 Bergman May 11, 1920 10 1,512,249 Sprague Oct. 21, 1924 2,080,777 Lebensart May 18, 1937 FOREIGN PATENTS Number Country Date 496,081 Great Britain Nov. 24, 1938 

